Standard Relay Diagram. 87 and 87a are the two contacts to which 30 will connect. Take this coolant fan relay for example.
The information is shown schematically but. In earlier days instead of plc or dcs like controllers relays are used as controllers. Ns for the br sr standard relay interlocking circuit.
Comparing to other controllers it is very cheap.
The guide incorporates a lot of practical. Comparing to other controllers it is very cheap. Just like basic house wiring we always want to control switch the hot wire. In earlier days instead of plc or dcs like controllers relays are used as controllers.